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MICROSTRUCTURE STUDY ON 16.5mol% CeO_2.ZrO_2.BY MEANSOF TRANSMISSION electron MICROSCOPE

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Acta Metallurgica Sinica(English Letters) 1997年第3期10卷 174-178页

作者： L-F. Li Z. Zhang and Y Y Li(Cryogenic laboratory chinese academy of sciences, Beijing {2., china)({4. of Metal Research, chinese academy of sciences, Shenyang 110015, china) Cryogenic Lab Chinese Acad of Sciences Beijing China

The microstructure of a fine-grained 16.5mol% CeO2.stabilized tetragonal zirconia polycrystal (Ce-TZP has been investigated by TEM and it is shown that the mi-crostructures of samples fractured at 2.8, 77 and 4.2.K change significantly. At 2.8K there is no stress-induced martensite but a few anti-phase boundaries (APBs) in tetragonal (t) parent phase. With a decrease in temperature, monoclinic (m) product or mariensite within retained t-phase appears. The morphologies are characterized as lenticular and block-like at 77 K and as lenticular and butterfly-like at 4.2.K. The relationship between microstructure and mechanical properties is also discassed in this paper.

关键词： microstructure stress-induced martensite mechanical property

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

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Science china(physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3, WANG Yong2. DU Xiaolong1, MEI Zengxia1, KONG Xianghe3, JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2. 4.1. State Key laboratory for Surface physics,{2., chinese academy of sciences, Beijing 100080, china 2. laboratory of electron microscopy,{2., chinese academy of sciences, Beijing 100080, china 3. College of physics and Engineering, Qufu Normal University, Qufu 2.3165, china 4. Beijing University of Technology, Beijing 10002., china 1. State Key laboratory for Surface physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. College of physics and Engineering Qufu Normal University 273165 Qufu China 3. laboratory of electron {2. Institute of Physics Chinese Academy of Sciences 100080 Beijing China 4. Beijing University of Technology 100022 Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30 rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron {2.. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.

electron dynamics in collisionless magnetic reconnection with a PIC simulation

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chinese Science Bulletin 2009年第3期54卷 456-460页

作者： GUO Jun1,2.1 School of Mathematics and physics, Qingdao University of Science and Technology, Qingdao 2.604.0}{4. 2.State Key {2. of Space Weather, chinese academy of sciences, Beijing 100080,{4. School of Mathematics and physics Qingdao University of Science and Technology Qingdao China State Key laboratory of Space Weather Chinese Academy of Sciences Beijing China

Two-dimensional particle-in-cell (PIC) simulation is used to investigate electron dynamics in colli- sionless magnetic reconnection, and the proton/electron mass ratio is taken to be mi /me = 2.6. The results show that the presence of a strong initial guide field will change the direction of the electron flow. The electron density cavities and the parallel electric field can be found in the electron inflow re- gion along the separatrix, and the electron inflow and density cavities only appear in the second and fourth quadrants. What is different from the results with a smaller mass ratio is that new structures appear in the diffusion region near the X line: (1) Narrow regions of density enhancement and density cavities can be found synchronously in this region; and (2. corresponding to the electron density changes near the X line, the strong parallel electric fields are found to occur in the first and third quadrants. These electric fields perhaps play a more important role in acceleration and heating electrons than those fields located in the density cavities.

关键词： PIC模仿磁链接导向场电子动力学

Adsorption and reaction of CO and O_2.on the Ag/Pt(110) surface studied by photoemis-sion electron microscopy

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chinese Science Bulletin 2001年第12期46卷 998-1002页

作者： HUANG Weixin & BAO XinheState Key laboratory of Catalysis, Dalian institute of Chemical {2., chinese academy of sciences, Dalian 11602., china State Key laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China

The Ag/Pt(110) model catalyst was prepared by evaporating silver on Pt(110). Adsorption and reaction of CO and O2.on Ag/Pt(110) surface were studied in situ by photo-emission electron microscopy (PEEM) during the pressure range of 10-5-10-2.Pa at 4.0 K. The Ag/Pt(110) surface consisted of Pt(110), AgPt interface and Ag area after annealing at 500 K. The dosing pressure of CO and O2.had a larger influence on their adsorption on the Ag area than on the Pt(110) and AgPt interface. Small Pt clusters formed on the Ag area and AgPt interface, which had a stronger ability to adsorb CO than Pt(110) terrace. The existence of Ag had an obvious influence on the kinetic of CO oxidation on Pt(110). No pattern was observed on the AgPt interface under the same condition when the formation of reaction-diffusion waves occurred on Pt(110).

关键词： silver Pt(110) carbon monoxide oxygen adsorption reaction photoemission electron microscopy.

A pulse radiolysis study on electron affinity of piperonal

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Science china Chemistry 2005年第5期48卷 476-480页

作者： MA Jianhua1, LIN Weizhen2. WANG Wenfeng2.& YAO Side2.1. College of Biology Engineering, Jimei University, Xiamen 36102.,{4. 2. Shanghai institute of Applied {2., chinese academy of sciences, Shanghai 2.1800,{4. 1. College of Biology Engineering Jimei University 361021 Xiamen China 2. Shanghai institute of Applied physics Chinese Academy of Sciences 201800 Shanghai China

The piperonal electron affinity was studied using pulse radiolysis technique. The electron transfer reaction process between piperonal and anthraquinone-2.sulfate was observed in the pH 7 phosphoric acid salt buffer. The transient absorption spectra of electron transfer re-action between piperonal and anthraquinone-2.sulfate were obtained, and the initial proof of the electron transfer between electron donor and acceptor was provided directly. The one-electron reduction potential of piperonal was determined to be ?0.4.7 V.

关键词： piperonal, pulse radiolysis, one-electron reduction potential.

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

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Science china(physics,Mechanics & Astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2. & WANG ShiJin1 1 Center for Space Science and Applied Research, chinese academy of sciences, Beijing 100190, china 2.Graduate University of chinese academy of sciences, Beijing 10004., china 1. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China 2. Graduate University of chinese academy of sciences Beijing 100049 China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2.04. the relativistic electron data from Fengyun-1 satellite from June 1999 to 2.05 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 4. REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 4.0 cm?2.srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 4. REE events, four strong REE events last a longer time period from 2.-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 4. events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

Investigation of a New Exsolved Cu-Fe-S Phase in“Abnormal Sphalerite”

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Acta Geologica Sinica(English Edition) 1991年第1期65卷 27-36,110-111页

作者： Li Jiuling Wang Su institute of Mineral Deposits, chinese {2. of Geolgical sciences,Beijing Beijing {4. of electron microscopy, chinese academy of sciences, Beijing institute of Mineral Deposits Chinese Academy of Geolgical Sciences Beijing China

A new exsolved copper-iron-sulfur phase in sphalerite has been found in the Dajing cassiterite- sulfidecopper-silver-tin deposit, Inner Mongolia, china. After investigating the optical properties, chemical composi-tion, crystal structure and exsolved Characters of the exsolved phase, the authors present important evidencefor its being a new exsolved copper-iron-sulfur phase mineral. Its formation mechenism is discussed in consider-ing heating experiments, phase equilibrium data and the geology of the deposit.

关键词： Ph Fe Abnormal Sphalerite Cu

Tensor Theory of High Energy electron Diffraction and Its Applications in Crystalography

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电子显微学报 1997年第4期 157-160页

作者： L. M.Peng (Beijing laboratory of electron {2., chinese academy of sciences, P.O. Box 2.2., Beijing 100080, P.R. china)

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关键词： Its and Diffraction Crystalography Applications

CRYSTAL STRUCTURE DETERMINATION AND IMAGE PROCESSING IN HIGH RESOLUTION electron microscopy

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电子显微学报 1991年第2期 213-214页

作者： F.H. Liinstitute of physics,{2., Beijing 100080,{4.

The development of high resolution electron microscopy(HREM) has providedan approach to determine the average structure of minute crystals and the localstructure of defected crystals. The high resolution electron microscope imagestaken under the Scherzer defocus condition mirror the projected structure ofexamined crystals if the sample is very thin. However, it is difficult to set the

关键词： PPDF CRYSTAL STRUCTURE DETERMINATION AND IMAGE PROCESSING IN HIGH RESOLUTION electron microscopy HREM